Question: Solve for $q$ : $q - 9 = 8$
Explanation: Add $9$ to both sides: $ \begin{eqnarray} \\ q - 9 &=& 8 \\ \\ {+9} && {+9} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-9 + q} &\hphantom{=}& \hphantom{8} \\ q &=& 8 {+ 9} \\ \end{eqnarray} $ Simplify. $ q = 17$